1. Field of the Invention
This invention relates to a signal transmission interface, more particularly to a signal transmission interface of a digital broadcast receiving device.
2. Description of the Related Art
A digital broadcast system is a type of broadcast system, such as a conventional HD Radio product, that uses digital compression and transmission technologies to transmit a digital audio signal. The digital broadcast system enables reproduction of original sound subsequent to receipt of the digital audio signal by a digital broadcast receiver. Compared with conventional analog FM and AM broadcast signals, a digital broadcast signal is less prone to interference during a process of transmission that can result in loss of fidelity. The following merits are attributable to digital broadcasting.
(1) Digital broadcasting provides increased resistance to interference, and is less prone to signal attenuation during transmission. As long as the digital audio signal is received, the original sound can be broadcast with fidelity.
(2) Although transmitting power is low, audio quality of transmission attains CD quality, thereby fulfilling high sound quality requirements for music.
(3) Movement of the digital broadcast receiver at a high speed does not adversely affect reception. Moreover, a digital broadcast network can operate as a “single frequency network”, which eliminates a need to change channel frequencies in order to tune in to all area programs and inconvenience associated with seeking an analog channel frequency.
(4) The utilization efficiency of the frequency spectrum is increased such that six CD quality stereo programs can be transmitted simultaneously. Moreover, non-audio digital service information can be transmitted at the same time as the digital audio signal, the non-audio digital service information being provided to a digital broadcast receiver of a display device for displaying pictures and text.
On account of these merits, application of the digital broadcast receiver in cars and homes is an increasing trend. However, integration of the digital broadcast receiver with portable media players (PMP), home sound systems, and other such consumer audio products currently requires a board connector having at least twenty-one pins, and the relatively large size of this board connector prevents easy integration of the digital broadcast receiver with these consumer audio products. Therefore, it is desired to provide a signal transmission interface for a digital broadcast receiver that is universal and has a reduced pin count so as to facilitate integration of the digital broadcast receiver with the consumer audio products.